WO2006029548A1 - A method for realizing handover between the bluetooth handset with bluetooth gategay - Google Patents

Abstract

The present invention provides a method for realizing handover between the bluetooth handset with the bluetooth gateway. the method including the following steps: the bluetooth gateway detects the signal's quality of the bluetooth handset which is communicating through it; when it finds the detected signal's quality of the bluetooth handset is below some value, it makes a handover request to the management server; the management server makes a handover decision according to the signal's quality that is detected by other bluetooth gateway hereabout; the handset establishes bluetooth connection with the new bluetooth gateway; the primary bluetooth gateway transfers the call to the new bluetooth gateway by use of the call forwarding function of the SIP; the new bluetooth gateway establishes bluetooth calling link with the handset. Thus, the handover is complete. Using the present invention it can realize that the bluetooth handset handover between different bluetooth gateways during it's communicating period.

Description

 Method for realizing Bluetooth mobile phone switching between Bluetooth gateways

 The present invention relates to the field of Bluetooth communication technology and IP telephony, and in particular to a method of call processing. Background technique

 SIP (Session Initiation Protocol) is an IP telephony signaling protocol proposed by the IETF (Internet Engineering Task Force). Its main purpose is to solve the signaling control in the IP network. SIP is used to initiate a session. It can control the establishment and termination of multimedia sessions attended by multiple participants, and can dynamically adjust and modify session attributes such as session bandwidth requirements, media types transmitted (voice, video, data, etc.), media. Codec format, support for multicast and unicast, etc. Specifically, SIP provides the following features:

 Name translation and user location: Ensure that the call reaches the called party, regardless of where the callee is.

 Feature Negotiation: It allows for agreement with the calling parties on the features supported.

 Call Participant Management: A participant in a call can introduce other users to join the call or cancel the connection to other users. In addition, users can be transferred or placed for call hold.

Call Feature Change: The user should be able to change the call characteristics during the call. In the prior art, there is a short-range wireless communication technology called Bluetooth, which operates in the 2.4 GHz ISM (Industrial-Science-Medical) band. The basic network structure of Bluetooth is a piconet consisting of one master device and up to seven slave devices. The master device and the slave devices use time division multiple access (TDMA) to communicate. With Bluetooth technology, devices can be connected in a cost-effective manner. The Special Interest Group (SIG) is a civil society organization that develops and directs Bluetooth specifications and applications. In its definition of Cordless Phone Profile, it proposes a Bluetooth-based cordless phone. The way, that is, a cordless telephone base station (hereinafter referred to as a Bluetooth gateway) as a master device and a cordless telephone handset (hereinafter referred to as a terminal) as a slave device are equipped with a Bluetooth wireless transceiver module, using Bluetooth for voice and control signals The transmission of the order. A cordless telephone landline (Bluetooth gateway) is connected to a fixed network, and a Bluetooth gateway can connect up to seven terminals. Unlike ordinary cordless phones, this cordless phone handset (Terminal) At the same time, it can be a cellular phone (hereinafter, the cellular phone with the function of the Bluetooth cordless phone is a Bluetooth phone). The above solution largely solves the problem of the use of the fixed telephone and the cellular telephone, and thus has a good application prospect. By combining the above two technologies, when the Bluetooth mobile phone is in the coverage of the Bluetooth gateway, the telephone can be called and received through the IP network, thereby saving the call charge. However, the SIG does not give a way for Bluetooth phones to switch between Bluetooth gateways. When a Bluetooth mobile phone in a call state moves from one Bluetooth gateway to another, it is impossible to avoid a call interruption. Summary of the invention

 In order to solve the above technical problem, the present invention provides a method for implementing a Bluetooth mobile phone to switch between Bluetooth gateways. The method is implemented in the network configuration environment of the present invention, wherein: a SIP registration server is connected to the local area network to provide a standard SIP registration server function.

The IP/PBX gateway is connected to the Internet and the PSTN network, and the Bluetooth mobile phone can communicate with the phone on the PSTN and the phone on the Internet. The management server is responsible for Bluetooth device management and switch management. Multiple Bluetooth gateways are connected to the local area network (LAN), which form a piconet with the Bluetooth handsets within its coverage.

 The method of the present invention includes the following steps:

 a) the first Bluetooth gateway detects the signal quality of the Bluetooth handset that is making a call through it; b) when the first Bluetooth gateway finds that the detected Bluetooth mobile phone signal quality is below a certain value, sends a handover request to the management server;

 c) the management server makes a handover decision according to the signal quality of the Bluetooth mobile phone detected by the other Bluetooth gateways near the first Bluetooth gateway, and selects the second Bluetooth gateway from the other Bluetooth gateways as the Bluetooth to be switched to Gateway

 d) the second Bluetooth gateway establishes a Bluetooth connection with the Bluetooth mobile phone;

 e) transferring the call of the Bluetooth mobile phone from the first Bluetooth gateway to the second Bluetooth gateway by using the call forwarding function of the SIP;

f) The second Bluetooth gateway establishes a Bluetooth call link with the Bluetooth handset. DRAWINGS

 The objects and advantages of the invention will be apparent from the description of the preferred embodiments of the invention. among them:

 Figure 1 is a system block diagram of a Bluetooth cordless telephone device (Bluetooth gateway or terminal);

 2 is a schematic diagram for explaining a network configuration of a Bluetooth cordless telephone device;

 3 is a flow chart for explaining switching between different Bluetooth gateways during a Bluetooth mobile phone call according to the present invention;

 4 is a flow chart for explaining related actions when a Bluetooth mobile phone joins a piconet where a Bluetooth gateway is located, according to the present invention;

 Figure 5 is a flow chart for explaining the related actions when a Bluetooth mobile phone leaves the piconet where the Bluetooth gateway is located, in accordance with the present invention. detailed description

 Figure 1 is a system block diagram of a Bluetooth cordless telephone device (Bluetooth gateway or terminal). In Figure 1, the Bluetooth cordless telephone device 100 is comprised of several functional modules. Among them, the Bluetooth cordless telephone application 110 provides various functions of the cordless telephone to the user, and the required voice is provided by the baseband controller 150; the required control information is determined by the SDP (Service Discovery Protocol) 170 and the TCS (Telephone Control Protocol) 120. provide. The standard communication protocol L2CAP (Logical Link Control and Adaptation Protocol) 130 multiplexes various protocols of the upper layer. The HCI (Host Control Interface). Driver 175 allows the transmission of standard HCI commands and receives the resulting response; and receives and transmits data through the L2CAP 130. The HCI transport layer 180 is optional. When the upper functional module and the lower functional module of the HCI transport layer are run on different processor platforms, the HCI transport layer is responsible for information transfer between the modules, and the physical transport type may be RS232. , USB, UART, PCI or PCMCIA; When the above two types of modules are running on the same processor platform, the information transfer uses shared memory, parameter transfer, message, etc., and the transport layer is no longer needed.

 The link manager 180 is responsible for receiving commands and data sent by the upper module and returning the result to the upper layer. The link manager 180 performs the corresponding functions through the baseband controller 150 and the radio transceiver 160. Link Management Protocol 140. Used for mutual communication between different Bluetooth device link managers. The baseband controller 150 operates in accordance with the commands of the link manager 180. The wireless transceiver 160 wirelessly transmits and receives information in accordance with standard specifications.

2 is a schematic diagram explaining a network configuration of a Bluetooth cordless telephone device. The SIP registration server 205 is connected to the local area network to provide the functionality of a standard SIP registration server. Bluetooth phone can The call is made through the IP/PBX gateway 210 and the phone on the PSTN and the phone on the Internet. The management server 215 is responsible for Bluetooth device management and handover management. The Bluetooth gateways 220, 235 and 250 and the Bluetooth handsets 225, 230, 240, 245 within their coverage form a piconet. The Bluetooth mobile phone 225, 230 and the Bluetooth gateway 220 form a first piconet, the Bluetooth mobile phone 240 and the Bluetooth gateway 235 form a second piconet, and the Bluetooth mobile phone 245 and the Bluetooth gateway 250 form a third piconet. Mobile phones that are within the coverage of the Bluetooth gateway can talk to each other or to the outside world via IP/PBX.

 Figure 3 is a flow chart for explaining the switching of Bluetooth handsets between different Bluetooth gateways during a call in accordance with the present invention. The Bluetooth gateway periodically (e.g., 10 minutes) looks up other Bluetooth gateways around and reports this information to the management server. The purpose of this step is to let the management server know the distribution of each Bluetooth gateway and know which other Bluetooth gateways are around a Bluetooth gateway. The Bluetooth mobile phone is talking through the first Bluetooth gateway, and the first Bluetooth gateway detects the signal quality of the Bluetooth mobile phone (S305).

 The Bluetooth mobile phone moves to the second Bluetooth gateway. The first Bluetooth gateway detects that the Bluetooth mobile phone signal quality is lower than a certain value, and issues a handover request to the management server (S310). The management server knows that the second Bluetooth gateway and the third Bluetooth gateway are near the first Bluetooth gateway according to the message in the handover request of the first Bluetooth gateway. It notifies the second Bluetooth gateway and the third Bluetooth gateway to detect the signal quality of the Bluetooth handset.

 The three Bluetooth gateways periodically (e.g., 1 second) detect the signal quality of the Bluetooth handset and report it to the management server. Based on the received data, the management server makes a decision as to when to switch to (S315). In this example, the management server decides to switch the Bluetooth handset to the second Bluetooth gateway. The management server notifies the three Bluetooth gateways of the handover decision. All three Bluetooth gateways stop periodic signal quality detection. The second Bluetooth gateway establishes a Bluetooth connection (S320) with the Bluetooth mobile phone, and the Bluetooth mobile phone joins the second Bluetooth gateway.

Thereafter, the call is transferred from the first Bluetooth gateway to the second Bluetooth gateway (S325) using the call forwarding function of SIP. This includes the following steps. First, the second Bluetooth gateway registers with the SIP registration server and notifies the management server. The management server notifies the Bluetooth gateway of the success of the Bluetooth mobile phone joining the second Bluetooth gateway. The first Bluetooth gateway utilizes the SIP call forwarding function to transfer the call to the second Bluetooth gateway. When the first Bluetooth gateway receives the message that the calling party agrees to the call transfer (in the SIP signaling, it is SIP OK), the Bluetooth mobile phone is notified to switch, and the call with the Bluetooth mobile phone is disconnected. The Bluetooth mobile phone disconnects from the Bluetooth connection of the first Bluetooth gateway. The first Bluetooth gateway cancels the registration of the Bluetooth mobile phone to the SIP registration server. Second Bluetooth network After the call forwarding message of the first Bluetooth gateway is received (in the SIP, it is INVITE), a Bluetooth call link is established with the Bluetooth mobile phone (S330). The process of establishing a Bluetooth call link includes: initiating a call request to a Bluetooth mobile phone; the Bluetooth mobile phone accepts the call, and establishes a Bluetooth voice channel, that is, an SCO connection. The second Bluetooth gateway establishes a voice channel (RTP connection) with the calling party, and the handover is completed.

 4 is a flow chart for explaining the related actions when a Bluetooth mobile phone joins the piconet where the Bluetooth gateway is located, in accordance with the present invention. When the Bluetooth mobile phone sends a message to the Bluetooth gateway requesting to join the piconet where the Bluetooth gateway is located (S410), the Bluetooth gateway agrees to establish a connection with the Bluetooth mobile phone (S420) and adds the Bluetooth mobile phone to the terminal list (S430), and simultaneously registers with the SIP service. The device registers the identifier of the Bluetooth mobile phone, and the identifier may be a Bluetooth address of the Bluetooth mobile phone, or may be an identifier assigned to the Bluetooth mobile phone by other means.

 Figure 5 is a flow chart for explaining the related actions of the present invention when a Bluetooth mobile phone leaves the piconet where the Bluetooth gateway is located. First, the Bluetooth gateway monitors the extent to which a Bluetooth mobile phone is about to leave the piconet with the Bluetooth gateway as the master device (S510). When the Bluetooth gateway finds any of the following facts, it considers that the Bluetooth mobile phone has left the piconet where the Bluetooth gateway is located: 1) The Bluetooth gateway reads the Bluetooth gateway and the designated Bluetooth mobile phone using the HCI command "Read-RSSI" defined in the Bluetooth standard. The signal strength indicator (RSSI) value of the Bluetooth link, when the value indicates that the signal quality is below the specified threshold; 2) the Bluetooth gateway uses the standard HCI command "Get-Link-Quality" to get a 1-byte value link Quality information, this value indicates that the link quality is below the specified threshold; 3) The Bluetooth gateway determines that the HCI event occurred when there is a broken link event with the specified Bluetooth handset. After detecting the above facts, the Bluetooth gateway deregisters with the SIP registration server (S520).

 While the invention has been shown and described with respect to the preferred embodiments the embodiments of the embodiments of the invention Various changes.

Claims

Rights request A method for implementing a Bluetooth mobile phone switching between Bluetooth gateways in a network comprising a plurality of Bluetooth gateways, the method comprising the steps of:  a) the first Bluetooth gateway detects the signal quality of the Bluetooth handset that is making a call through it; b) when the first Bluetooth gateway finds that the detected Bluetooth mobile phone signal quality is below a certain value, sends a handover request to the management server;  c) the management server makes a handover decision according to the signal quality of the Bluetooth mobile phone detected by the other Bluetooth gateways near the first Bluetooth gateway, and selects the second Bluetooth gateway from the other Bluetooth gateways as the Bluetooth to be switched to Gateway  d) the second Bluetooth gateway establishes a Bluetooth connection with the Bluetooth mobile phone;  e) transferring the call of the Bluetooth handset from the first Bluetooth gateway to the second Bluetooth gateway using the call forwarding function of SIP;  f) The second Bluetooth gateway establishes a Bluetooth call link with the Bluetooth handset.  2. The method according to claim 1, after receiving the handover request, the management server notifies other Bluetooth gateways in the vicinity of the first Bluetooth gateway to detect the signal quality of the Bluetooth handset, and determines whether to perform handover based on the signal quality.  3. The method of claim 1 wherein the management server notifies the first Bluetooth gateway and the other Bluetooth gateways of the switching decision after making the handover decision, and the Bluetooth gateway thereby stops periodic signal quality detection.  4. The method of claim 1, the Bluetooth gateway detects the signal quality of the Bluetooth handset by: 1) the Bluetooth gateway uses the HCI command defined in the Bluetooth standard. "Read_RSSI" reads the signal strength indicator (RSI) value of the Bluetooth gateway and the Bluetooth mobile phone Bluetooth link; 2) The Bluetooth gateway uses the standard HCI command "GetJLink-Quality" to obtain link quality information of 1 byte value. :  5. The method of claim 1 wherein the other gateways adjacent to the Bluetooth gateway are periodically queried by the first Bluetooth gateway for reporting to the management server.  6. The method of claim 1, each Bluetooth gateway periodically detecting the signal quality of the Bluetooth handset and reporting the signal quality to the management server. 7. A method according to any one of claims 1-6, wherein the step of using the call forwarding function of SIP for call forwarding comprises: The second Bluetooth gateway registers the Bluetooth mobile phone with the SIP registration server, and notifies the management server;  The management server notifies the first Bluetooth gateway of the success of the Bluetooth mobile phone joining the second Bluetooth gateway;  After the first Bluetooth gateway receives the call forwarding message from the calling party, the Bluetooth mobile phone is notified to perform the handover, and the call with the Bluetooth mobile phone is disconnected;  The Bluetooth mobile phone disconnects from the Bluetooth connection of the first Bluetooth gateway, and the first Bluetooth gateway cancels the registration of the Bluetooth mobile phone to the SIP registration server;  The second Bluetooth gateway receives the SIP call transfer message from the first Bluetooth gateway.  8. The method of claim 7, the Bluetooth gateway can notify the Bluetooth handset of the call forwarding event by: 1) using the Bluetooth TCS Information message; 2) indicating that the handover is to be made in the Cause field in the TCS Disconnect message.